AMERICAN STANDARD SIZES

Recommended Use. In general, the 3% interference in all thread sizes is recommended for harder, less malleable materials such as cast iron. 5% interference is recommended for 3/8" (M10) diameter and up for softer materials such as aluminum. The 8% interference is recommended for sizes #10 (M4) through 5 16 " (M8), for use in aluminum. All interferences are based on the use of tap drill sizes which achieve 75% of internal thread. Sizes smaller than #10 are available. Metric sizes available.

ISO 9001:2008 CERTIFIED
FINE THREADS
THREAD 3% 5% 8%
10-32 .1603/.1615 .1616/.1630 .1631/.1649
12-28 .1834/.1848 .1849/.1866 .1867/.1887
1/4+28 .2144/.2158 .2159/.2176 .2177/.2197
6/16+24 .2737/.2753 .2754/.2774 .2775/.2799
3/8+24 .3337/.3353 .3354/.3374 .3375/.3399
7/16+20 .3926/.3946 .3947/.3970 .3971/.4001
1/2+20 .4551/.4571 .4572/.4596 .4597/.4625
9/16+18 .5178/.5200 .5201/.5228 .5229/.5261
5/8+18 .5803/.5825 .5826/.5848 .5849/.5891
3/4+16 .6901/.6925 .6926/.6950 .6951/.6999
COARSE THREADS
THREAD 3% 5% 8%
10-24 .1512/.1528 .1529/.1545 .1546/.1578
12-24 .1787/.1803 .1804/.1820 .1821/.1853
1/4+20 .2030/.2050 .2051/.2071 .2072/.2108
5/16+18 .2592/.2614 .2615/.2638 .2639/.2679
3/8+16 .3151/.3175 .3176/.3202 .3203/.3247
3/8+14 .3709/.3737 .3738/.3769 .3770/.3818
1/2+13 .4250/.4280 .4281/.4316 .4317/.4367
9/16+12 .4878/.4910 .4911/.4950 .4951/.5003
5/8+11 .5349/.5385 .5386/.5428 .5429/.5485
3/4+10 .6602/.6642 .6643/.6691 .6692/.6752

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